I have gone through this process a few times now, bringing Thunder with me into France, Switzerland, Germany, Spain, and Italy via plane. While the process might be slightly different for each country, bringing a dog into most places in Europe from the US is relatively straight forward. From what I understand, one exception to this rule would be the UK and Ireland which I believe require mandatory quarantine periods, so we have always avoided those destinations even for layovers.
First, the dog must be older than 15 weeks. It is possible to transport dogs younger than 15 weeks into some EU/Schengen Zone countries, but not all. For dogs younger than 15 weeks, you have two options.
1. The young dog must be nursing and dependent on its mother, and the mother needs to comply with the rules for dogs older than 15 weeks (needs a current rabies vaccination).
2. You can sign a Health Declaration stating that since the animal’s birth, it has had no contact with wild animals.
*Not all EU counties allow you to transport dogs younger than 15 weeks. Click here to see which countries do allow it.
For dogs older than 15 weeks, you are going to need a rabies vaccine and the certificate. The animal must wait 21 days after a “primary” rabies vaccination before it will be allowed into the EU.
A rabies vaccination is considered a primary vaccination by the EU when:
It is the animal’s first rabies vaccination.
It is the first rabies vaccination received after a new microchip is implanted.
The previous vaccination was expired when the latest vaccination was given.